GPS (Newell, Shaw, Simon) was an attempt to construct a general problem
solving mechanism that could solve problems in a new area given
domain-specific knowledge about that area.

GPS is a generalized state-space search mechanism. It has the following
components:

A set of states and operators that change states.
Specification of start and goal states.

A procedure for identifying differences
between states.

A table of connections that
connects observed differences with
operators that may be relevant for reducing those differences.

GPS works by determining the difference between
the current state and the
goal state and selecting operators relevant to reducing that difference.
Hopefully this will give direction to the search and make it more efficient
than a blind state-space search.